Nature Notes – June 2015

Among the migrant birds which are here for the summer is a small warbler called the Whitethroat. From a very much reduced population in the 1960s and 1970s, believed to be caused by drought conditions around the edge of the Sahara, Whitethroats have now recovered, and are quite well represented in our area. Here they live in hedges and areas of bramble, and further east on the Sandlings heaths they are common in the gorse. The males are quite easy to pick out. They have a rusty back, grey head and a sharp area of white on the throat. Helpfully, they usually sing their brief scratchy song from a prominent position, or even during a brief song flight. Look out for them. Confusingly there is also a Lesser Whitethroat, rather scarcer, skulking and much harder to see. Luckily it has a very different song, but you need to know it to find Lesser Whitethroats.

The nest-box camera which I was given two years ago is giving a fascinating look at the Great Tits in a nest-box on our house. The female has been sitting on six eggs which, at the time of writing, have just hatched and the young are being fed by both of the pair. Just before the beginning of June, all being well, these youngsters will have fledged and left the box. They will stay as a family for several weeks – it is quite easy to pick out the young tits by their much duller plumage.

I have been sent some interesting pictures of several creatures in a Sweffling garden (including a splendid Grass Snake). One is of a large beetle, very dark and with large jaws like a miniature Stag Beetle. The real Stag Beetle is even larger, with brown wing-cases and enormous jaws in the male looking like antlers. It does occur in Suffolk but I have yet to see one in this area. The one in the picture is called the Lesser Stag Beetle. Both have larvae which feed in rotting wood, usually in large tree trunks.

By mid-summer, there are a lot more bumblebees about, with many smaller workers as well as the large queens. Gardens are increasingly important for these bees, with their continuous supply of flowers through the season. In addition, different bumblebees have different lengths of tongue and can take nectar from flowers of different depths. For instance, common species like the Red-tailed Bumblebee (Bombus lapidarius) and the Garden Bumblebee (Bombus hortorum, with yellow bands on the thorax and abdomen and a white tail) have long tongues, and can feed from flowers with quite long floral tubes. In contrast, the Buff-tailed Bumblebee (Bombus terrestris, with fewer yellow bands and a buff tail) has a short tongue, and favours shorter flowers like composites and Ice Plant. However, it will often cheat, and bite a hole at the end of a flower tube to get nectar normally available only to the long-tongued species. This means that it will also fail to pollinate the flower. Gardeners may find neat little holes in the spurs of broad bean flowers, where short-tongued bumblebees have been stealing the nectar.

One of the summer damselflies is a particularly handsome insect, although rarely seen around garden ponds. Instead it can be seen along the river Alde – a very beautiful metallic blue body with striking wide bands of indigo across the wings. These give it the name of Banded Demoiselle. The female is quite different, although also a large and beautiful damselfly. Her body is not blue but a metallic green colour. The wings are slightly dark but with no indigo bands.

By Geoffrey Abbott